If you think you are pregnant, then you need to take a pregnancy test to confirm that you are pregnant. Delayed menstruation can be from other causes. It's dangerous to just try to "make yourself bleed", especially since you don't even know if you are pregnant or not.

You can try drinking parsley tea (just pour boiling water from the kettle over the leaves and strain it if you wish), if you aren't pregnant than that should help (apparently).

If the home pregnancy test still comes up negative but you have no period than you will have to go a walkin clinic or your family doctor to get a blood test done to check if you are pregnant. I know it is a hassle, why do they even sell pregnancy tests anyway if they can't pick up a small amount of the hormones? But at least it will give you peace of mind.

Other reasons you may be late is stress, if you lost weight or are overweight, exercise or lack thereof, hormonal issues, etc.

Good luck.